use a standard import instead of re-declaring the intrinsic in test

Author: folkertdev

tests/ui/simd/intrinsic/generic-elements-pass.rs

@@ -1,7 +1,9 @@
 //@ run-pass
 //@ ignore-emscripten FIXME(#45351) hits an LLVM assert
 
-#![feature(repr_simd, intrinsics)]
+#![feature(repr_simd, intrinsics, core_intrinsics)]
+
+use std::intrinsics::simd::{simd_extract_dyn, simd_insert_dyn};
 
 #[repr(simd)]
 #[derive(Copy, Clone, Debug, PartialEq)]
@@ -19,15 +21,9 @@ struct i32x8([i32; 8]);
 #[rustc_intrinsic]
 unsafe fn simd_insert<T, E>(x: T, idx: u32, y: E) -> T;
 
-#[rustc_intrinsic]
-unsafe fn simd_insert_dyn<T, E>(x: T, idx: u32, y: E) -> T;
-
 #[rustc_intrinsic]
 unsafe fn simd_extract<T, E>(x: T, idx: u32) -> E;
 
-#[rustc_intrinsic]
-unsafe fn simd_extract_dyn<T, E>(x: T, idx: u32) -> E;
-
 #[rustc_intrinsic]
 unsafe fn simd_shuffle<T, I, U>(x: T, y: T, idx: I) -> U;